1. Field of the Invention
The present invention relates to a laser apparatus or arrangement having a laser oscillator and a subsequently connected laser amplifier, which has an entry region for the laser beam to be amplified as coming from the laser oscillator and an outlet for the amplified or reinforced laser beam and which is provided with a folding mirror which is located lying opposite the entry region for the laser beam to be intensified or strengthened and bolstered.
2. Description of the Prior Art
The most common or customary manner for production and generation of laser beams of a prescribed output capacity is the employment of a laser oscillator. The combination of a laser oscillator of small or nominal capacity and a laser intensifier or amplifier is employed especially then when a laser beam of high output capacity and simultaneously good beam quality and/or high modulation band width is required. Disadvantages of conventional or previous laser intensifiers or amplifiers, so-called single-pass intensifiers or amplifiers are among others the poor or bad utilization of the intensifying medium via the still weak oscillator beam in the input region of the intensifier or amplifier, the large construction length necessary with weak intensifying media and the increased constructive cost and complexity for separate oscillators and intensifiers or amplifiers in comparison to power-capacity or performance laser oscillators.
In order to reduce or decrease some of these disadvantages of the intensifier or amplifier, the laser beam with a different known intensifier or amplifier, a so-called multi-pass intensifier or amplifier can pass multiply through the intensifying medium. Here in place of the window to the rear in the incidence direction of the oscillator beam, as provided with a single-pass-intensifier or amplifier there is provided a folding mirror or reflecting means is provided at which the laser beam is reflected. The construction length required for attaining a prescribed intensification or amplification is reduced and the regions occurring or arising in the input or entry region of single-pass intensifiers or amplifiers with hardly utilized intensifying medium are made smaller or reduced. Disadvantageous with a multi-pass intensifier or amplifier, however, is that a space separation of beams running or extending back and forth proceeding in a small angle as to each other can occur first in a large spacing from the intensifying or amplification tube, whereby a compact construction of the system is made more difficult.